Main and Header Have Fixed Padding and Margin

[andyleach]

These element have fixed padding and margin, while our goal might be to not use utility classes, it might be worth using some very simple ones to handle this rather than attaching it to the element itself. This way we can have more flexibility with child elements we end up creating. Example below:

[tyleruebele]

We'll need to rethink much of the _layout layer to reduce it to suitable defaults, instead of what suited the style guide. That said, utility classes are not the answer. Padding the main might be a job for a consuming project's _theme layer.